First few failures/what I've learned.

So I finally got everything to work on the printer. Sort of. I had some interesting failures, slowly moving towards success. So when other people finally get their printers working, some of this may help.
My first calibration print just turned out to be very very squashed, in the Z axis. I was printing the calibration piece, and all that came out was a square about .4 mm thick. I didn;t know what to attribute this to, so i changed the number of base layers to 8, and gave it another shot. Not really much changed, though it did get a little bit thicker. 

Turns out, I had the build plate calibrated incorrectly. What i had been doing was, having the plate as low as possible so that when it went all the way down to G0 -200, it was pushing into the VAT. 

To calibrate the build plate correctly, loosen the vertical locking knob, Put the build plate at home, then execute the G0 Z-200 F200 command. When the build plate hits the VAT, it will push the hollow cylinder up before it pushes the VAT down. This gets the z- Axis ready. 

After doing that correctly, I executed another print. The build plate went up to home, then down, just like it was supposed to. (also this time i added four calibration pieces just because). The Build plate went down, and started printing correctly, but it turns out i hadnt correctly tightened the ball joint knob, and for some reason, the build plate ended up rotating quite a bit. This had a strange effect, so that some of the calibration pieces came out halfway formed and cut off at a diagonal. 

I thought i was all set. I calibrated the build plate again, made sure everything was tight, and went over the build plate with my silicone spatula to make sure nothing was in there. I had the calibration print, and i added another wierd object just for fun to the slicing model. I sliced it, and hit play. the plate went up, and then back down. and started printing as i hoped. The build plate didnt rotate or anything, and by looking under the tank, up at the layers, i could see everything curing. The timer said a little under 2 hours so i left.
Turns out, The viewsonic projector decided to disconnect at two different points during the print. This made for some wierd effects, and a failed print, as you can see in the photos. But yea. Sometimes the projector disconnects (or effectively reboots?) and shows a blank blue screen, so my entire build plate showed this wierd viewsonic home screen. You can actually see the text printed on there. Very strange.
I'm going to tweak my sleep settings as i have a feeling this may have been the problem, but all in all, dont leave the printer. It will misbehave.

Last thing, there are a lot of bubbles when i print, and i worry if this going to cause problems... 


  • ThijsThijs Member, Backers
    Yeah that blue screen shows up here as well, but it only occurs (so far) when my main screen is going to screensaver.
  • sjensensjensen Member, Backers
    Thanks for the information.
    I had the blue screen thing happen to me on my last print. I'll check the screensaver settings.
  • sabotagesabotage Member, Moderator, Backers, Ultimate Backer
    Never thought of this being an issue, but, since I'm using the RPi with CWH as my print host, I know that setup does disable screen blanking, sleep and other power savings settings that would cause this.

    Thanks for pointing it out for the benefit of everyone!
    imageBacker(Ultimate Package - delivered on July 1, 2015)
  • ThijsThijs Member, Backers
    But to get back on that calibration topic: you are saying you should lower the build plate so the vertical cylinder is pushed up. But do you then lower it a bit more so the VAT is pushed down as well?
  • JHSJHS Member, Backers
    Was testing the projector and printer last night before I go out and buy screws to mount it to the plate and also found that ViewSonic splash screen comes up when the main screen goes to screensaver mode. Changed all of my power settings to never turn off just as a precaution.

    @Thijs I think he means to loosen the vertical locking knob and let the build platform get pushed up a little before locking it? Like the gif in the user manual:


    You can see the silver vertical cylinder isn't touching either the top or bottom but somewhere in the middle.
  • Joseph_OsbornJoseph_Osborn Member, Backers
    Thijs said:

    But to get back on that calibration topic: you are saying you should lower the build plate so the vertical cylinder is pushed up. But do you then lower it a bit more so the VAT is pushed down as well?

    No! The vat should sit naturally at the top of its springs with the build platform pressed flush to it and locked down tightly. If you have the platform locked so hard against the vat that it compresses the springs, it's pushing down too much.
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    To summarize along with my experiences...

    1) Disable all screen savers and power savings options for the monitors on the computer attached to the Draken. This includes the monitor with the desktop. If you are walking away and concerned about power, turn off the monitor.

    2) When starting a print using the Draken CW profiles, start with the print arm all the way at maximum height after it triggered the limit switch. Attach the build plate to the build plate knob until secure. Loosen the ball head screw so the build plate can pivot. Loosen the print arm knob until the metal cylinder drops down and the build plate knob is resting on the print arm. Start the print. The build plate will travel down towards the vat. Make adjustments to plate position as it gets closer to the vat to align it. When the plate reaches the vat, the print arm will continue to travel while the build plate is resting on the vat. The arm will stop and you will press down on the build plate knob 2-3 times, compressing the springs on the vat and allowing it to return to its original position. Tighten down the print arm knob. Hold the ball head in one place and start to tighten the ball head knob. The head can rotate if you don't secure the head while tightening the knob. The delay should be long enough to allow you to make the final adjustments before the first layer is exposed. This can be adjusted in the start gcode if you need more time or the delay is too long.
  • kniborknibor Member, Backers
    I do the same thing as rkundle, I'm using my normal laptop to print most of the times and I set it up in such a way that when my laptop is connected to power than it's never turning of ;)! (It does when runnig on my battery... So I really need to plug in the charger)

    I think rkundla method just works fine but since the vat goes down in an angle I also press al the corners down ;)! But this might be unusefull...

    Also most of the thime I only losen the print arm knob ;)! The ball screw should be still in place after some printers ;)!
  • soupysoupy Member, Backers
    I learned to turn off my computer's monitor sleep function after printing out a resin "Acer" logo. But now i've decided to just use my old surface pro 2 as a dedicated PC for the draken. That way i can always leave that one running while the draken prints.
  • jacobjacob Member, Backers
    edited October 2015
    Got the printer up and running again today, and discovered that sometimes, very early on in the print, the build plate likes to rotate clockwise, and is restrained by the edges of the vat. But everything with the build plate was screwed in tight. So i disassembled it, cleaned it out, and put it back together. Still got a messed up print. 
    I am not sure what forces are actually pushing or pulling the build plate to rotate like this, but I can tell you that it is too easy, to rotate the build plate. When i opened up the plate, and the black knob structure, there seemed to be an extra degree of freedom, so even when everything is screwed in tight, and calibrated, it can still rotate quite easily. Video attached below.
    Anyone else have this rotation problem? Im more inclined to believe, i screwed something up than that the build plate has such serious design flaw. 

    I am barely applying any pressure, there is some resistance, but not so much that some peel force couldnt rotate the plate.

    But still: here are some successes from yesterday, as well as something fun i tried. I plucked all the bristles off a cheap electric toothbrush, and used double stick tape to get a piece of sandpaper attached. I used it to get rid of support marks, and it works  reallllly well.

  • EdwardEdward Member, Backers, Ultimate Backer
    I had the same problem. The build plate has two metal sheets tightened with some little screws. Unscrew all those little screws, take off the bottom sheet and you'll see another big bolt in the middle. You just have to tighten that bolt and put back the bottom sheet.
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    It depends on which part is rotating. Is the silver cylinder in the build arm secure? It can be tight enough to keep it from dropping, but not tight enough to keep it from rotating. Also, the knob screw has to be tight to the ball head. How tight is the ball head knob? Looks awkward to get at with the handle from the build arm screw in the way (from the video at least).

    If it was the screw inside the build plate, the ball head would be camming out of the slot or wobbling. Do you see that?

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